Switching means



8, c. c. WHITTAKER 2,403,837

- SWITCHING MEANS I Filed March 18, 1944 2 Sheets-Sheet 1 WITNESSES: f8 INVENTOR Char/es dlffi/flaie/f BY 00M (9, Wu

ATTORNEY Oct. 8, 1946.

c. c. WHlT TAKER SWITCHING MEANS Filed March 18, 1944 2 Sheets-Sheet 2 WITNESSES:

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INVENTOR I Char/es 6T Wfi/ffdker BY Pdf ATTORNEY Patented Oct. 8, 1946 UNITED STATES PATENT OFFICE SWITCHING MEANS Charles C. Whittaker, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 18, 1944, Serial-No. 527,050

'7 Claims. 1

My invention relates to control apparatus, and more particularly to a pneumatically operable time delay switch.

The Government of the United States has been granted a certain royalty-free license for governmental purposes with respect to the invention herein described.

The present war has brought into use the electrically driven torpedo but in such torpedoes for certain operations gas flasks are still necessary for the operation of certain devices. While it is ordinarily not important to provide for certain specific operations, as the disconnection of an electric motor from the propulsion means, on the final run, it does become rather important how the system of control is utilized fora torpedo during practice runs.

In the electric torpedo now in use the propulsion motor is connected to the battery, when the torpedo is fired, as soon as a trigger on the torpedo is actuated by a dog in the firing tube. The torpedo propulsion propellers thus often are rotating before the torpedohad cleared the tube, that is, the propulsion propellers are up to full speed or at least a relatively high speed by the time the propellers pass the torpedo tube shutters.

The connection of the propulsion motor is effected by a pneumatically operated switch. Since the few air flasks or gas flasks still used on torpedoes carry gas at about 3000 pounds per square inch, it is apparent that the pneumatic switch has an extremely small time constant. The instant the trigger on the torpedo is actuated, the switch interconnecting the propulsion motor and battery is actuated. Since the propeller blades are not loaded, not being in the water, while still in the tube the propulsion mo.- tor comes up to speed almost instantly.

One object of my invention is the provision of a delay in the starting of a torpedo motor after firing of a torpedo.

A broad object of my invention is the provision of a time delay for a pneumatically actuated switch.

It is also an object of my invention to prevent rotation of the propellers of a torpedo while moving out of the firing tube while the torpedo is being fired.

The objects hereinbefore recited are merely i1- lustrative, because many other objects and advantages will become apparent from a study of the following specification and the accompanying drawings, in which:

Figure 1 is a side view, with some parts shown 2 in longitudinal section, of a pneumatically operable switch;

Fig. 2 is a front view of certain upper parts, looking in the direction indicated by the arrows at the ends of line IIII of the showing in Fig. 1;

Fig. 3 is a plan view of the showing of Fig. 1; and

Fig. 4 is a schematic showing of one application of my time delay switch, the one application being in connection with a propulsion control for an electrically operated torpedo.

To better understand my contribution to the art reference may first be had to Fig. 4 showing one illustrative application of my pneumatically operated time limit switch.

In Fig. 4, the torpedo firing tube I is shown as having a dog 2 for actuating the trigger 3 for operating the starting valve 4 when the torpedo 5 is fired from the tube I. For the operation of the pneumatic devices, a gas flask l, which may contain air under high pressure as 3000 to 4000 pounds per square inch, is utilized. This flask is connected to the valve 4 actuated by the starting trigger 3 and, when opened, supplies air under pressure through pipe 8 to a four-way valve B and thence to the pneumatic switch It during one stage of operation and for another stage of operation to the four-way valve 9, and thence through the tube II to the interior of the practice head 6. v

A battery I 2 is utilized for supplying the energy to the propulsion motor [3,. This propulsion motor I3 is of the series type having no commutating poles but is controlled for operation at constant speed by the governor mechanism It for shifting the brush ring I5 so that constant motor speed is maintained.

The four-way valve is also designed to be operated by the governor mechanism to shift the four-way valve from the connection shown to such a connection that the flask l is connected to the chamber of the practice head and the conduit l6, for supplying the pneumatic switch with gas pressure, is connected to the pressure relief valve IT.

A better understanding of some of the details of my invention can probably behad from a study of typical sequence of operation during a practice run. This operation is as follows: The instant the torpedo is fired, the trigger arm 3 is actuated by the dog 2 and the starting valve 4 is opened, whereupon gas from the flask I is admitted under high pressure to the conduits 8 and 8'. The conduit 8' leads to various devices on the torpedo not constituting part of the invention four-way valve 9 and as shown in the dotted lines provides gas pressure to the pneumatically operated switch III which is thereupon, after a relatively short time interval, explained hereinafter, operated to close the contacts I8 to thus establish a circuit from the battery |2 through the motor field winding l9, the motor armature, conductor 20, contacts I8 back to the battery I2. The motor thus, in a suitable time after the torpedo leaves the firing tube, assumes the propulsion of the torpedo driving it, through suitable gyroscopic controls, towards the target. If a practice run is only contemplated, no war head is used, but the practice head 6 is used.

The pneumatically operable switch comprises a nipple 41 to be connected to the conduit l5, and a cylinder 48 for housing the piston 49, This piston is designed as a. valve at the region 50 and coacts with the valve seat in the region 01' the mid portion of the cylinder 48. The reduced upper end of the piston is rigidly connected to the inverted cup-shaped member 52 having the reentrant shoulder connection 53. The upper outer portion of the cylinder is provided with a collar 54, and a spring 55 under compression is disposed between the collar 54 and the reentrant shoulder connection to thus normally hold the piston in the position shown.

The piston is provided with a rod 50 having the stop nut 56 secured at its upper end. On this rod is disposed a contact member 51 suitably insulated from the rod by the insulating sleeve 58. The contact member 51 slides freely on the piston rod 50 and is designed to resiliently engage the contact members l8.

To effect this resilient engagement of the contacts, a spring 59 under compression is disposed between the lower face of the contact members 51 and a suitable circumferential outer ledge 22 on the outer portion of the cup-shaped member 52.

To obtain adjustment for the compressive force of spring 59, I may position a ring 2| between the shoulder or ledge 22 and the spring 59. This ring preferably is rectangular in section and of a selected axial length, or dimension, to selectively alter the compression of spring 59.

The piston is designed to fit somewhat loosely in the cylinder so that when pressure is suddenly admitted to the conduit |6 by the operation of starting valve 4, there is some leakage of the gas'past the piston and the piston is thus not operated with too much impact so as to injure any portion of the device. However, once the piston is forced upwardly, the conical portion of valve 5|] engages the valve seat 5|, thus providing a substantially perfect seal against any leakage of the gas from the switch.

It should be remembered though that this leakage of fluid past the piston 49 while in upward motion, does by no means provide a suflicient time constant for the switch contacts Hi to prevent operation of the propeller driving motor before the torpedo propellers have cleared the firing tube shutters. I, therefore, have devised the special timing means shown in the upper portion of Fig. 1.

My special pneumatic switch is rigidly secured to a panel board, the torpedo, locomotive, ship, or other machine, by plate elements 23. On the lower plate 23 I disposed the guide sleeves 24 for guiding the contact 51 that is slidably disposed on the upper end piston rod 50' of piston 49. In line with the guide sleeves 23 and held by the herein described. The conduit 8 leads to the same clamping bolts, as shown, I dispose the sleeves 25.

To the upper ends of the four sleeves 25, I connect the horizontal plate 26 for mounting the bearings 21, 28 and 29. Bearing 21 supports the shaft for the pinion 3D and inertia member or disc 3|. Bearing 28 supports the shaft for the pinion 32 and spur gear 33. Bearing 29 provides a pivot at the left for the gear sector 34.

The gear sector 34 is so designed, being generally T-shaped, and so mounted on its bearing 29 that it tends to rotate clockwise, but for the position of the parts shown is prevented from rotating in the clockwise direction by the link 35 of the toggle mechanism 36 interconnected, or coupled, to the gear section 34 and the movable contacts 51.

To the mid portion of the contacts 51, I rigidly connect a pair of vertically disposed arms 31. At the upper end of these arms 31 and disposed between the upper ends of the arms 31, the bottom end of the link 35 is pivotally secured at point or pivot 42. A second link 38 has its lower end pivotally secured at pivot 39 to the link 35 and has its upper end pivotally secured at pivot 4| to the stem 40 of the gear sector 34.

The pivots 4| and 42 are substantially in vertical alignment and both lie in a vertical line falling to the right of bearing 29. The pivot center 39 lies to the right of the vertical line including the pivot centers 4| and 42.

The pivot centers 4| and 42 are in effect in the axes of the projecting pins 43 and 44. On the outer ends of pins 43 and 44, the tension springs 45 and 46 are mounted and these springs, by virtue of an initial tension of a desired value given to them when mounted on the pins, tend to move links 38 and 35 counterclockwise and clockwise, respectively, with reference to each other. Such movement is, however, prevented by pin 10 mounted on link 35.

The link 35 has a projection 60 which provides a rest, or stop, limiting the downward, or clockwise movement of gear sector 34. The spur gear 33 is provided with pin 6| normally resting on a. suitable lug on stem 40 of the gear sector. The arrangement and design of all the parts of the timing mechanism are such that the parts are all in the position shown when the movable contact 51 is not in contact with the stationary contacts l8.

In operation, when the torpedo is fired, the trigger 3 is actuated to open the starting valve 4. Almost instantly the switch piston 49 is moved up, however, since the movable contact 51 is loose on the piston rod the upward movement of the cup-shaped member 52 merely compresses spring 59. The contact 51 thus tries to close against contacts l8 and in so doing the bars 31 are moved upwardly. Since the toggle mechanism 36, for the position of its elements and for this stage of operation, provides a rigid connection between contact 51 and the stem 40 oi the gear sector 34, the gear sector is moved counterclockwise. This operation of the gear sector rapidly drives the spur gear 33 in a clockwise direction, which, in turn, drives the inertia disc in a counterclockwise direction. The inertia member in accelerating prevents a too rapid rertical motion of contact 51.

After a relatively short vertical movement of contact 51, spur gear 33 will have rotated through a sufficient angle so that pin 5| trips the link 35 at region 63 and thus breaks the rigidity of the toggle. Links 35 and 38 move counterclockwise and clockwise,respeotively. with 'respectto each other, and thusinstantly free contact 5'l'to move to rapidly make contact with the stationary contacts I'B.

For the particular application of my device shown, a time delay of of a second will usually suffice. If a longer time delay is required, ring 2| may be replaced with a narrower ring or ring 2| may be threaded vto the cup-shapedhousing so that the initial compression force of spring'59 may be adjusted to the time delay needs of the application, or use, .of my device.

At the instant the toggle breaks, inertia disc 3| will be rotating at a relatively high speed and if it should be stopped suddenly, the pinion teeth would be damaged. I, therefore, provide spur gear 33 with a toothless zone between points 65 and 61 on the periphery of the gear 33. The arrangement is such that this zone is opposite the pinion just as the toggle is broken by Din 6|. Inertia disc 3| is thus permitted to coast to rest.

To insure reengagement of the teeth of spur gear 33 with the pinion 30 I cut the first tooth at the end 61 of the toothless region to a sharp edge as shown.

When air is released .from the cylinder, spring 55 causes the switch to open, the gears revolve in the reverse direction and the toggle is automatically reset byhaving the lower end of sector 34 strike the rest 60 on the link 35.

The time element can also be changed by varying the weight of the inertia member or by attachin weights in balanced relation to the inertia disc 3|.

While I have shown but one embodiment and a modification and have shown my device in a particular application, it is readily apparent that my time delay switch is not limited to the application made nor is it limited to the particular details shown, but my invention is only to be limited by the scope of the claims hereto appended.

I claim as my invention:

1. A pneumatically. operated time limit switch, in combination, a cylinder, a piston provided with a rod disposed within the cylinder, means for supplying gas under pressure to the cylinder to operate the piston, stationary contacts, a movable contact, slidably mounted on the piston rod, for bridging the stationary contacts, a toggle mechanism coupled to the movable contact, a spring coacting with the piston and movable contact to bias the movable contact toward the stationary contact upon operation of the piston, and time-limit means operable after a given movement of the movable contact toward the stationary contacts for breaking the toggle mechanism to thus release the movable contact so that it makes rapid contact with the stationary contacts.

2. In a timing device for a switch, in combination, a pivoted gear sector, an inertia disc, a transmission gear between the gear sector and the disc to drive the disc when the gear sector is moved angularly about its pivot, a link pivoted at one of its ends to the gear sector between the gears of the sector and its pivot, a movable switch element, a second link pivotally coupled at one of its ends to the movable switch element by a second pivot disposed remote from its said one end to the other end of the first link, said second pivot being off center so that the links form a toggle mechanism, a spring and stop for maintaining the toggle mechanism in fixed relation in one of its overcenter positions, whereby movement of the switch element causes movement of the gear sector, and means operable by movement of the gear sector to break the overcenter position of the toggle mechanism.

3. In a pneumatically operable switch, in combination, a cylinder, means for admitting fluid to the cylinder, a piston in the cylinder, a piston rod projecting from the cylinder, a pair of stops on the piston rod, a contact slidably mounted on the piston rod, .a spring under compression disposed between one stop on the piston rod and the contact slidably mounted on the piston rod to bias the slidable contact against the other stop on the piston rod, a pair of stationary contacts disposed to be bridged bythe slidable contact when the slidable contact is in its actuated position, inertia means mounted to be set in motion, a toggle-joint coupling between the slidable contact and the inertia means, means for holding the toggle-joint in one overcenter position to provide a rigid operative connection between the inertia means and the slidable contact, whereby movement of the slidable contact toward its operated position sets said inertia means in motion with the inertia means retarding the motion of the slidable contact, and means operable by a predetermined movement of the inertia means for moving the toggle-joint to its other overcenter position to thus eliminate the rigid operative connection between the slidable contact and the inertia means.

4. In a machine having an operating charac teristic whereby a machine element is, when operated, moved with relatively high speed from one position to another position, in combination, a machine element having, a member slidably mounted thereon, a pair of speed stops on the member, and a compression spring disposed between one stop and the member to bias the member against the other stop; means for moving the machine element from one of its positions to its other position in the direction of the biasing force of the spring on the member; an inertia element; a pivotally mounted arm operatively engaging the inertia element to set the inertia element in motion when the arm is moved about its pivot; a toggle-joint operatively interconnecting the member and the arm; means for holding the toggle-joint in a given overcenter position to provide a relatively rigid arm-operating interconnection between the member and arm when the machine element is moved in the direction of the biasing force of the compression spring on the member; and means operable by the inertia element for moving the toggle-joint over center from its given overcenter position to thus break the arm-operatin interconnection between the member and arm.

5. In a machine having an operating characteristic whereby a machine element is, when operated, moved with relatively high speed from one position to another position, in combination, a, machine element having, a member slidably mounted thereon, a pair of speed stops on the member, and a compression spring disposed between one stop and the member to bias the member against the other stop; means for adjusting the spring compression, means for moving the machine element from one of its positions to its other position in the direction of the biasing force of the spring on the member; an inertia element; a pivotally mounted arm operatively engaging the inerti element to set the inertia element in motion when the arm is moved about its pivot; a toggle-joint operatively interconnecting the member and the arm; means for holding the toggle-joint in a given overcenter position to provide a relatively rigid arm-operating interconnection between the member and arm when the machine element is moved in the direction of the biasing force of the'compression spring on the member; means operable by the inertia element for moving the toggle-joint over center from its given overcenter position to thus break the arm-operating interconnection between the member and arm, whereby the member after an initial time delay is freed to move by action of the compression spring against one of the stops on the machine element.

6. In an inertia controlled time delay device, in combination, an operating member, an inertia disc mounted for rotation, a first pinion coupled to the disc, a rotatably mounted spur gear meshing with the pinion, a second pinion coupled to the spur gear, a pivotaily mounted gear sector meshing with said second pinion, whereby a relatively high gear ratio is provided between the gear sector and the inertia to accelerate the disc to a high speed for a small movement of the gear sector, a toggle-joint, having its links restrained to a given overcenter position, operatively connected to the gear sector and the operating member, and means operated by the spur gear for moving the toggle-joint over center from the given overcenter position to thus break the operative connection between the operating member and gear sector. a

'7. In an inertia controlled time delay device, in combination, an operating member, an inertia disc mounted for rotation, a first pinion coupled to the disc, a rotatably mounted spur gear meshing with the pinion, a second pinion coupled to the spur gear, a pivotally mounted gear sector meshing with said second pinion, whereby a relatively high gear ratio is provided between the gear sector and the inertia to accelerate the disc to a high speed for a small movement of the gear sector, a toggle-joint, having its links restrained to a given overcenter position, operatively connected to the gear sector and the operating member, and means operated by the spur gear for moving the toggle-joint over center from the given overcenter position to thus break the operative connection between the operating member and gear sector, said spur gear having no teeth over a relatively small section of its periphery whereby the operative interconnection between the spur gear and inertia disc may be interrupted when the toggle-joint is broken over center to thus thereafter make the operation of the disc independent of the operation of the gear sector.

CHARLES C. WHIT'I'AKER. 

